Data-Driven Respiratory Gating Outperforms Device-Based Gating for Clinical ¹⁸F-FDG PET/CT

Abstract

Methods 144 whole-body 18 F-FDG PET/CT examinations were acquired using a Discovery D690 or D710 PET/CT scanner (GE Healthcare), with a respiratory gating waveform recorded by an external, device-based respiratory gating system. In each examination, two of the bed positions covering the liver and lung bases were acquired with duration of 6 minutes. Quiescent period gating retaining ~50% of coincidences was then able to produce images with an effective duration of 3 minutes for these two bed positions, matching the other bed positions. For each exam, 4 reconstructions were performed and compared: data-driven gating (DDG-retro), external devicebased gating (RPM-gated), no gating but using only the first 3 minutes of data (Ungated matched), and no gating retaining all coincidences (Ungated full). Lesions in the images were quantified and image quality was scored by a radiologist, blinded to the method of data processing. Results The use of DDG-retro was found to increase SUV max and to decrease the threshold-defined lesion volume in comparison to each of the other reconstruction options. Compared to RPMgated, DDG-retro gave an average increase in SUV max of 0.66±0.1 g/mL (n=87,p<0.0005). Although results from the blinded image evaluation were most commonly equivalent, DDG-retro was preferred over RPM-gated in 13% of exams while the opposite occurred in just 2% of exams. This was a significant preference for DDG-retro (p=0.008,n=121). Liver lesions were identified in 23 exams. Considering this subset of data, DDG-retro was ranked superior to Ungated full in 6/23 (26%) of cases. Gated reconstruction using the external device failed in 16% of exams, while DDG-retro always provided a clinically acceptable image. Conclusion In this clinical evaluation, the data-driven respiratory gating technique provided superior performance as compared to the external device-based system. For the majority of exams the performance was equivalent, but data-driven respiratory gating had superior performance in 13% of exams, leading to a significant preference overall.

Quantitative comparison of data-driven gating and external hardware gating for 18F-FDG PET-MRI in patients with esophageal tumors

“…4. This result is in contradiction with Walker et al (Walker et al 2020) who however only visually investigated the noise level in the liver and bone marrow in PET/CT data and found almost equivalent noise levels in images based on DDG, external hardware gating, and a static image from 50% of the coincidence data. In another study, evaluating respiratory gating based on signals extracted from PET raw data using PCA, the results showed significantly lower noise levels in images based on respiratory gating signals extracted from PET raw data using PCA compared with gated images based on respiratory gating signals extracted from external bellow device (Fürst et al 2015).…”

Prospective data-driven respiratory gating of [68Ga]Ga-DOTATOC PET/CT

“…Limitations of this study includes that no comparison of DDG versus device-based gating was performed. This has, however, been published previously on retrospective [ 18 F]FDG data, in terms of evaluating the respiratory signal, quantitative measurements and image quality, and where the performance of DDG was found superior [15]. Further, the PET/CT findings were not validated by comparison with a standard of reference.…”

“…The respiratory signal generated with PCA-based DDG has been found to correlate well with that from devices, and showed better performance in terms of robustness, image quality, and higher standardized uptake values (SUV). Introduction of DDG into PET clinics might allow for replacement of device-based gating and make routine use of respiratory gating clinically feasible [14][15][16].…”

Phantom and clinical assessment of small pulmonary nodules using Q.Clear reconstruction on a silicon-photomultiplier-based time-of-flight PET/CT system

“…Existing researches suggested that respiratory movement leads to overestimations of radiotracer-avid target volume and reduction in the SUV due to the recorded number of coincidence events tending to distribute in a larger volume 28 . A data-driven respiratory gating function is now available on the GE system, which has shown out-performance than the device-based gating 29 . The respiratory gating system can be employed in a future study to facilitate the improvement of spatial resolution and quantification accuracy, especially when radiotherapy treatment planning is desired 30 – 32 .…”